Sentences that don't inspire confidence

'John is building a knife-throwing machine!' my mother told me brightly. Oh dear.

Happily, it turns out he is building this not, as I feared, for some bizarre new hobby the two of them have taken up, but as a stage prop for the local theatre company's latest production. Phew.

He was also going to build an exploding sewing machine until he checked the health and safety regulations that say any actor on stage with it would have to be wearing fire retardant clothing, and there would have to be a paid firefighter waiting in the wings in case something went wrong. So they're just going to use the sound of a sewing machine exploding instead.